Lifi Security System

int a;
void setup() {
  // put your setup code here, to run once:
pinMode(A0,INPUT);
Serial.begin(9600);
pinMode(8,OUTPUT);
pinMode(9,OUTPUT);
pinMode(10,OUTPUT);
pinMode(11,OUTPUT);
pinMode(7,OUTPUT);



}
int pin_i;
int pin_1;
int pin_2;
int pin_3;
int pin_4;

void loop() {
  // put your main code here, to run repeatedly:
  int arr[]={1,2,3,4};
  for (int j=0;j<3;j++){
  digitalWrite(7,HIGH);
  delay(200);
  digitalWrite(7,LOW);
  delay(200);}
for(int i=0;i<4;i+=1){
  delay(200);
  digitalWrite(7,HIGH);
  a=analogRead(A0);
  delay(1300);
  Serial.println(a);
  
  if(a>850){
      arr[i]=LOW;
  }
  else{
    arr[i]=HIGH;
  }
digitalWrite(7,LOW);
delay(1000);
}
digitalWrite(8,arr[0]);
digitalWrite(9,arr[1]);
digitalWrite(10,arr[2]);
digitalWrite(11,arr[3]);

delay(5000);
digitalWrite(8,LOW);
digitalWrite(9,LOW);
digitalWrite(10,LOW);
digitalWrite(11,LOW);


}